Philadelphia police

Boy's family sues Philly, officer accused of shooting, killing 12-year-old

A former Philadelphia police officer is criminally charged with murder in the March 2022 shooting death of 12-year-old Thomas "TJ" Siderio in South Philadelphia

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Nearly two years after a 12-year-old was shot and killed, his family has sued the City of Philadelphia and the plainclothes police officer accused of gunning him down.

In a lawsuit filed last month, the family of Thomas "TJ" Siderio seeks damages after the 12-year-old was killed in South Philadelphia in March 2022.

A former Philadelphia police officer is accused of shooting and killing a 12-year-old boy. NBC10's Aaron Baskerville spoke with the boy's family.

Prosecutors said Siderio was on the ground and unarmed when police officer Edsaul Mendoza fired a fatal shot through his back in South Philadelphia.

"As a result of Defendants’ misconduct, T.S.’s survivors seek compensation for the economic and non-economic losses they have suffered as a result of his death, including medical expenses, funeral and burial expenses, costs of estate administration, the pecuniary value of the services, support, comfort, care and society he would have provided to them had he not died and damages for the incalculable emotional and psychological losses they have suffered as a result of
T.S.’s death," the lawsuit states.

The fired Philadelphia police officer accused of shooting Siderio was charged weeks later with murder and has remained jailed without bail awaiting his criminal trial, according to court records.

Mendoza was a member of the PPD's South Task Force. He was fired a few weeks after the shooting.

Police said Siderio used a stolen gun to fire a shot into the back passenger window of an unmarked police car. The plainclothes officers inside were looking for a teenager they wanted to interview related to a firearm investigation, police said. The officers saw two kids, Siderio and an unnamed 17-year-old, and drove the car around the block and next to them to initiate a stop.

However, District Attorney Larry Krasner later said that according to grand jury documents, the officers may have stopped the boys for a traffic violation -- going the wrong way down a street on a bicycle.

Thomas Siderio faces forward in a photo.
Thomas Siderio, 12, was shot dead by a Philadelphia police officer after allegedly firing at an unmarked car with four plainclothes officers inside.

Krasner said the unmarked car's emergency lights came on in almost the same moment Siderio fired the shot at their car. Prosecutors said it was unclear from video whether the boy knew it was a police vehicle when he fired, but the investigation was ongoing.

An officer was treated for injuries to his eye and face caused by broken glass.

Two officers then got out and opened fire, initially missing the boy, police said. Officer Mendoza, however, gave chase down the city block and fired two more rounds, one of which struck Siderio in the right side of his back and exited through the left side of his chest, Krasner said.

“It is certain that [Siderio] had stopped running and he was possibly surrendering ... and he was essentially facedown on the sidewalk," Krasner said, noting the boy was in a pushup position looking back toward the officer.

The lawsuit notes that Siderio “was essentially facedown on the sidewalk” and “in a position similar to a push-up.”

There are additional resources for people or communities that have endured gun violence in Philadelphia. Further information can be found here.

Police had initially said Siderio was holding a gun as he ran away. But prosecutors later said that there were several indications Mendoza knew Siderio had dropped the gun and was down on the ground before shooting him.

"When Officer Mendoza fired the third and fatal shot, he knew that 12-year-old, 5 foot tall, 111-pound T.S. no longer had a gun, and therefore, no ability to harm him," the lawsuit states.

Mendoza's criminal trial is set to begin in May, according to court records. The attorney in his criminal case had no comment about the new lawsuit.

NBC10 has also reached out to the City for comment, but had yet to hear back.

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